It is well known to those skilled in the art that aromatic hydrocarbons are a class of very important industrial chemicals which find a variety of uses in petrochemical industry. It is also well known to those skilled in the art that catalytically cracking gasoline-range hydrocarbons produces aromatic hydrocarbons such as, for example, benzene, toluene, and xylenes (hereinafter collectively referred to as BTX) in the presence of catalysts which contain a zeolite. The product of this catalytic cracking process contains a multitude of hydrocarbons including unconverted C.sub.5 + alkanes, C.sub.5 + alkenes, C.sub.5 + cycloalkanes, or combinations of two or more thereof; lower alkanes such as methane, ethane, and propane; lower alkenes such as ethylene and propylene; and C.sub.9 + aromatic compounds having 9 or more carbon atoms per molecule. Recent efforts to convert gasoline to more valuable petrochemical products have focused on improving the conversion of gasoline to more valuable aromatic hydrocarbons in the presence of zeolite catalysts. For example, a gallium-promoted zeolite ZSM-5 has been used in the so-called Cyclar Process to convert a hydrocarbon to BTX. The aromatic hydrocarbons can be useful feedstocks for producing various organic compounds and polymers. However, heavier, less useful aromatic compounds having 9 or more carbon atoms per molecule (C.sub.9 + aromatic compounds) are also produced by the conversion process. Furthermore, it is well known to one skilled in the art that some hydrocarbon conversion catalysts such as the type L zeolite-based catalysts are very sensitive to sulfur poisoning by a sulfur-containing compound. See, for example, WO96/00269, WO96/00270, WO96/37298, and WO96/37299. Because the catalysts are sensitive to sulfur poisoning, the process is generally carried out under a condition such that sulfur or a sulfur compound is substantially absent. Such a condition requires substantial removal or reduction of the sulfur or sulfur compound thereby increasing operation cost of the process and, consequently, the product cost. Therefore, development of a catalyst and a process for improving the conversion of a hydrocarbon, especially in the presence of a sulfur compound, to the more valuable BTX would be a significant contribution to the art and to the economy.